Automatic safety saw-guard.



F. W. PLEASANGE.

AUTOMATIC SAFETY SAW GUARD.

APPLICATION FILED SEPT. 21,1914.

1,127,509. Patent-,ea F6119, 1915.

FREDERICK W. PLEASANCE, OF CLEVELAND, OHIO.

AUTOMATIC SAFETY SAW-GUARD.

Specification of Letters Patent.

Patented Feb. 9, 1915.

Application :filed September 21, 1914. VSerial No. 862,642.

T0 all @IJ/0m it may concern Be it known that I, FREDERICK 7. Pnnns- ANCE, a citizen ofthe United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Automatic Safety Saw-Guards, of :which Vthe following is a specification.

This invention relates to saw guards for circular saws, and has for its object to provide an improved guard provided with a looking device which locks .the guard in closed or safety position except `when a piece of board or other material is ,presented to the saw, when by means of a trigger -the lock is released and the guard is permitted to lift to the extent necessary `,to allow the board to pass thereunder, and after it passes, the guard dropsand is automatically llocked again until the next operation. The .guard therefore remains in locked position except when the saw is in use.

In the accompanying drawings: Figure 1 is a side elevation showing the guard in locked position. Fig. 9. is adetail of the adjustable fastening device for the guard bracket. Fig. 3 is a side elevation showing the guard in raised position. Fig. 4 is a detail in perspective of the locking device. Fig. 5 is a detail in perspective of the trigger which operates the locking bolt and Fig. (i is a detail in perspective of the counterbalance.

Referring specifically to the drawings, 6 is the saw table and 7 is the saw, and 6a in Fig. 8 indicates a board which is being sawed.

8 is the guard or hood which ts over the saw and incloses the part thereof projecting above the table, and this hood has a vertical upwardly projecting bar or stem 14C which works through an opening between the horizontal bracket arms 13, which may conveniently be made of angle iron, and which are secured to the top of the spreader 17 by bolts 21 extending through holes 20, a series of which are provided to permit adjustment of the spreader toward or from the saw. The spreader is supported by means of a clamp 18 fastened to the under side of the table, and this clamp is adjustable by means of bolts 18a working in a slot 18", permitting variation in the horizontal and vertical position of the spreader. A lever 16 is pivoted at one end to the stem 14; and is fulcrumed on a bolt 16 which may be adjusted to any one of the holes 20a in the spreader 17, according to the desired position of the latter. At its outer end the lever has an adjustable weight 19 to counterbalance the weight of the guard. The stem 14 is Vprovided with an adjustable stop 15 which by contact with the brackets 13 limits the lift `of the guard. The stop is shown in full lines in Fig. 1 in one position, and in dotted lines in another position, being adjusted according to the thickness of the material to be sawed.

Mounted upon the outer end of the brackets 13 is a latch casing 12 having therein a sliding bolt 12b pressed by a spring 12a to engage in a notch' 14a in the bar 14, and when this bolt is so engaged lifting of the hood or guard 8 is prevented. The latch bolt is automatically released by means of an vangular rod .11, the upper end of which fits through the bolt, as shown in Fig. 1, and the lower arm of which works through a guide 8a on the hood 8 and is connected at its end to a trigger 10 which is pivoted to the nose 9 of the guard and depends at its lower end below the same in position to be struck by a board advanced toward the saw.

In operation, when a board on the saw table is entered under the nose 9 of the guard it strikes the trigger 10 and swings the same, causing the rod 11 to pull back the bolt 12b against the tension of the spring 12a, thereby unlocking the guard, which then lifts as the board passes thereunder. After the board has been run through, the guard drops by its own weight and the latch bolt again engages in the notch to lock the guard against accidental lift. The adjustments of the spreader 17 are desirable under certain conditions, as when saws of diiferent sizes are used, the larger sized saws requiring that the spreader be set backward and the smaller sizes requiring that it be set forward or toward the saw. It is obvious that normally the saw guard is in safety position and will be automatically locked and unlocked under the conditions described.

The invention is not limited to the exact structure illustrated and described, but may be embodied in various modified structures, within the scope thereof.

l/Vhat I claim as new is l. Thecombination with a vertically movable saw guard, of a latch engageable with the guard to hold the same in lowered position, and a trigger located at the front of the guard in position to be struck and operated by the material to be sawed, and connected to the latch and adapted to release the same and allow the guard to lift.

2. The combination of a bracket, a vertically movable saw guard having a bar projecting upwardly beside said bracket, a latch mounted on the bracket and engaging the bar to normally lock the guard in lowered position, and a trigger operatively connected to the latch and adapted to release the same, to allow the guard to lift.

3. The combination with a lifting saw guard, of a latch operatively engaging the same to normally hold it in lowered position, and means automatically actuated by material presented to the saw to release said latch and permit the guard to lift.

4. The combination of a spreader, an adjustable bracket thereon, a saw guard having an upright bar guided in said bracket, a counter-balance lever connected to said guard and adjustably fulcrumed on the spreader, and a latch mounted on said bracket and engageable with said bar.

5. The combination with a vertically movable saw guard, having an inclined nose at the front, of a latch engaging said guard when in lowered position, a trigger mounted on said nose in position to be struck and operated by a piece of material presented thereto, and a connection between the trigger and the latch, adapted to release the latter when the former is operated.

6. The combination of a vertically movable saw guard having an upright notched bar, a bracket overhanging the guard adjacent said bar, a latch mounted on said bracket and engageable in said notch to hold the guard in lowered position, a trigger at the front of the guard, in position to be operated by a piece of material presented thereto, and a connection between the trigger and the latch, adapted to release the latter when the former is operated.

ln testimony whereof, I afliX my signature in presence of two witnesses.

FREDERICK W. PLEASANCE.

Witnesses:

JOHN A. Bo-MMHARDT, EDWARD J. HOBDAY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

